At present, it is suggested that senile demantia represented by Alzheimer's disease causes serious change in central cholinergic nervous system, which results in deterioration of function thereof Perry, E. K. and Perry, R. H. "Biochemistry of Dementia", page 135 (1980), John Wiley & Sons.,!.
Accordingly, a compound having repair capacity (e.g. survival effect and neulite stretching effect) and protective action of nerve cells can be effectively used as a remedy or a preventive for senile demantia represented by Alzheimer's disease, Down's syndrome, Huntington's chorea, intellectual/learning disturbance (e.g. amnesia, memory disorder, etc.), and aftereffect and neuropathy caused by deterioration of acetylcholinergic nervous system function due to head injury, cerebral operation, drug intoxication, circulatory disorder, cerebral metabolic disorder, encephalitis, etc. J. W. Geddes et al., Science, 230, 1179-1181 (1985)!.
Heretofore, NGF (nerve growth factor), GM1 (ganglioside) and the like have merely been known as the compound having repair capacity for nerve cells degeneration as described above. NGF is described, for example, in Neuroscience Hefti, F. et al., 14, 55-68 (1985)!, Journal of Neuroscience Frantz Hefti, 6, 2155-2162 (1986)!, Proc. Natl. Acad. Sci. USA, L. R. Williams et al., 83, 9231-9235 (1986)!, Science L. E. Kromer, 235, 214-216 (1986)! and the like. In addition, GM1 is described, for example, in Science Fred J. Roisen et al., 214, 577-578 (1981)!, Brain Res. M. V. Sofroniew et al. 398, 393-396 (1986)!, Brain Res. M. Gradkowska et al., 375, 417-422 (1986)! and the like.